Re: beginner question about storing binary data in buffers, seeing binary data in a variable, etc

From:
"Alf P. Steinbach" <alfps@start.no>
Newsgroups:
comp.lang.c++
Date:
Fri, 04 Jul 2008 23:35:56 +0200
Message-ID:
<xKqdnQ_WqrTZCvPVnZ2dnUVZ_hjinZ2d@posted.comnet>
* darren:

Im working on an assignment that has me store data in a buffer to be
sent over the network. I'm ignorant about how C++ stores data in an
array, and types in general.


A textbook would be good resource.

If i declare an array of chars that is say 10 bytes long:
char buff[10];
does this mean that i can safely store 80 bits of data?


Yes.

When i think of an array of chars, i think each spot in the array as a
sequence of 8 1's or 0's. Is this a correct visualization?


No. A byte can be more than 8 bits. The number of bits per byte for a given C
or C++ implementation is CHAR_BIT, from <stddef.h>.

 I guess
my question here is why do most buffers seem to be implemented as char
arrays?


Are they?

 Can any binary value between 0 and 255 be safely put into a
char array slot (00000000 to 11111111).


It depends what you're really asking.

If you provided a concrete example and what you expected as result, one could
say whether that was correct or not.

But a char has guranteed at least 256 possible bitpatterns (minimum 8 bits), yes.

 Why not implement a buffer using uint8_t ?


That's not presently a standard C++ type.

Obviously I have a very loose grasp on how buffers are saving data,
and how a receiver gets this data on their end. I understand the
sockets stuff, just not the buffer-specific stuff. Any enlightenment
would be most appreciated.


See above.

Cheers, & hth.,

- Alf

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